In the related art, various screen devices are used for shielding, sun-shading, or insect-proofing of openings, such as windows, or entrances in buildings, such as houses, office buildings and so on.
As typical examples of the screen device as described above, there is a roll screen device in which a screen can be wound around a roller pipe for storage and withdrawn for setting up, and a roll screen device provided with a coil spring mechanism for accumulating a resilient force generated by rotation of a roller pipe to be used for winding the screen for storage is also well known.
The coil spring mechanism facilitates opening and closing, that is, operation of setting up and storage. Therefore, taking advantage of this characteristic, there is proposed a screen device in which a roller pipe can be moved without pivotally supporting the same in order to facilitate assembly and mounting of the device in a compact part configuration.
FIG. 8 shows an example, in which a screen 5 which can be withdrawn from a roller pipe 2, wound around the same for storage, and in association with the parallel movement of the slide bar 1 can be set up and opened freely between fixed frames 3, 4. The roller pipe 2 is slidable along a guide rail 10 by a runner 7 provided at the upper end. The roller pipe 2 is provided with a coil spring restoration mechanism 8 for providing a resilient force in the opposite direction of the rotation of the withdrawal of the screen 5, that is, for in the direction of winding of the screen 5. The screen device shown in FIG. 8 includes a runner 6 for a slide bar 1, a cover member 11, a lower rail 12, a locking member 13 as lock mechanism, an engaging member 14 and an unlocking member 15.
FIG. 9 shows another example. This example is a screen device which is openable and closable in the vertical direction, and includes two roller pipes 2A, 2B. The roller pipes 2A, 2B each are also provided with the coil spring restoration mechanism 8 and the screen 5 is mounted thereto. In association with movement of the slide bar 1, the screen 5 can be set up or wound for storage. In order to open and close in the vertical direction, the roller pipes 2A, 2B can be moved by being guided by both end guides 9 along the guide rails 16.
However, the screen devices described above, which are easy to wind the screen for storage has considerable disadvantages.
In the screen device shown in FIG. 8 in which the slide bar 1 moves parallel in the lateral direction, the upper end of the roller pipe 2 is slidable along the guide rail 10 by the runner 7. However, since the lower end is simply adjacent to the lower rail 12 in a free state, in the rotation in association with winding of the screen 5, i.e., the reverse rotation of the screen 5 in the direction of winding caused by the resilient force, a tensile force in the lateral direction which is applied to the roller pipe 2 tends to be unevenly distributed in the direction of the height of the roller pipe 2, and hence the roller pipe 2 is inclined to interfere with the smooth storage and withdrawal of the screen 5, which may result in difficulty of smooth and stable opening and closing operation.
In order to overcome this disadvantage, it has been considered to provide a runner which comes into abutment with the lower rail 12 at the lower end of the roller pipe 2. However, it is not easy to provide well-balanced stable slidability equivalent to the runner 7 at the upper end to the runner at the lower end due to the self-weight or deformation of the roller pipe 2, the screen 5, and the slide bar 1.
In addition, in the screen device shown in FIG. 8, since the lower end of the lower pipe 2 is free, there are inevitable problems such that the screen is deformed and flapped by wind or by contact with human body, and hence difficulty in setting up or storage is encountered, and passage of insects or dust cannot be prevented.
In the screen device shown in FIG. 9, it is very difficult to keep the end guides 9 of the roller pipes 2A, 2B balanced in the horizontal direction during the opening and closing operation, and in fact, in the event that the roller pipes 2A, 2B are inclined, disabling the opening and closing operation cannot be avoided. This problem is also caused by uneven tensile force generated at the roller pipes 2A, 2B upon rotation in the normal and reverse directions.
In the screen device shown in FIG. 9, the influence due to the deformation of the screen 5 caused by wind or contact with human body also cannot be avoided.
Even though the runner is attached to the guides 9, it is extremely difficult to maintain the sliding balance between the right and left sides.